The REACT Initiative

1. Miguel Vilaplana – Boeing Research & Technology Europe The REACT Initiative

2. Motivation: Trajectory Synchronisation in the Future ATM System • A New ATM Paradigm: Trajectory Based-Operations (TBO) • Key feature of the target concept of operations proposed by SESAR and NextGen: • Collaborative management of business trajectoriessupported by advanced trajectory-based automation tools • Trajectory-based automation tools rely on trajectory prediction • To support the interoperability between disparate trajectory-based automation tools, there is a need for mechanisms to synchronise Trajectory Predictors (TPs) • TP synchronisation is a key prerequisite for the SESAR/Next Gen concepts • The REACT project has focused on one of the types of information that can be shared between TPs to achieve synchronisation: the Aircraft Intent

3. A bit of terminology • Business Trajectory: • Represents the business/mission intention of an airspace user • Evolves through a collaborative planning process that involves users and ATM service providers and whose outcome should be a trajectory that results in minimum deviations from the user preferences • Interoperability is a property referring to the ability of diverse systems to work together (inter-operate) • A key necessary condition for the interoperability of trajectory-based automation tools is the synchronisation of the underlying TPs • The synchronisation of two TPs results in a minimally acceptable difference between the trajectory outputs of those TPs (this minimally acceptable difference depends on the applications supported by the TPs)

4. BUSINESS TRAJECTORIES Towards Trajectory Based Operations (TBO) ANSP1 ANSP4 AOC2 ANSP2 ANSP3 City B ANSP= Air Navigation Service Provider AOC= Airline Operations Centre ANSP1 AOC1

5. TRAJECTORY RELATED INFORMATION Towards TBO: Interoperability and TP Synchronisation ANSP1 ANSP4 AOC2 ANSP2 ANSP3 ANSP1 AOC1

6. TRAJECTORY RELATED INFORMATION DMAN CD&R FMS FP FP FMS ATFM ASAS FDPS FMS FMS FMS AMAN Towards TBO: Interoperability and TP Synchronisation ASAS=Airborne Separation Assurance System ATFM=Air Traffic Flow Management FDPS=Flight Data Processing Tool CD&R=Conflict Detection and Resolution TP2 TP4 TPR TP3 TP1 TPI TPN TPK TPH TP6 TP5 AMAN= Arrival manager DMAN= Departure manager FMS= Flight Management System FP=Flight Planning TPL TPP

7. Trajectory Prediction (Air or Ground) Flight Intent Intent Generation Infrastructure Trajectory Computation Infrastructure Aircraft Intent Predicted Trajectory Initial Conditions Airborne Automation System ? Flight Plan Actual aircraft state (position, speed, weight…) Flight Commands & Guidance Modes Tactical Amendments to Flight Plan Actual Trajectory Pilot Aircraft Environmental Conditions More Terminology: Trajectory-Related Information Trajectory Predictor (TP) Real World AT or ABOVE FL290

8. Trajectory Prediction (e.g., flight management system) Flight Intent Flight Intent Aircraft Intent Aircraft Intent Ground Predicted Trajectory Airborne Predicted Trajectory Flight Intent Information Aircraft Intent information Predicted trajectory information Sharing Trajectory-Related Information Airborne TP Intent Generation Infrastructure (1) Trajectory Computation Infrastructure (1) Data COM Infrastructure Intent Generation Infrastructure (2) Trajectory Computation Infrastructure (2) Ground TP TP PROCESS 2 (e.g., arrival manager)

9. The Aircraft Intent Description Language (AIDL) • Two levels in the language grammar: lexical and syntactical • Lexical Level: Instructions • Instructions are atomic inputs to the Trajectory Engine that capture basic commands and guidance modes at the disposal of the pilot/FMS to direct the operation of the aircraft • Syntactical level: Operations • Operations are sets of compatible instructions that, when simultaneously active, univocally determine the ensuing aircraft motion • With a reduced set of instructions (AIDL alphabet), any possible aircraft operation can be formally specified in such a way that the ensuing aircraft motion is unambiguously determined

10. The REACT Project Requirements Elicitation for an AIDL that supports Consistency across TPs • Eliciting requirements for a language that can serve as a standard means for sharing aircraft intent information between TPs • The language shall be independent of the • Operational context and application served by the TPs • Physical location of the TPs • Communication means Consortium: Aircraft Intent Description Language

11. The Scope of REACT Air-Air Next generation FMS FMS Air-Ground AOC 2 AOC 1 Next Generation FDPS FDPS Ground-Ground AMAN DST ATFM DST

12. Translator R-2 Translator 2-K Translator I-2 Translator I-R Translator R-K Translator 2-5 TRAJECTORY RELATED INFORMATION: AIRCRAFT INTENT Translator I-H Translator R-P Translator R-5 Translator I-5 Translator H-5 Translator 5-K Translator H-L Translator K-P Translator L-5 Translator 5-P N·(N-1) ÷ 2 TRANSLATORS Translator L-P Aircraft Intent Synchronisation in the future TBO without a standard AIDL… TP2 TPR TPI TPK TPH TP5 TPL TPP

13. AIDL Translator I-AIDL Translator H-AIDL Translator 2-AIDL Translator R-AIDL Translator K-AIDL Translator P-AIDL Translator 5-AIDL Translator L-AIDL N TRANSLATORS AIDL as a Standard supporting TP Synchronisation in the future TBO TP2 TPR TPI TPK TPH TP5 TPL TPP

14. REACT Approach • Elicitation process based on uncovering the commonalities existing between the ways in which different TPs model aircraft intent information • Superset of the aircraft intent information used by any two TPs that need to synchronise with each another • Use of the theoretical language structured as a reference to describe the requirements • The standard AIDL would include the aircraft intent description “dialects” used by the individual TPs, which could map their aircraft intent model to a subset of the AIDL • Focus on information content and structure

15. REACT Contributors

16. The Remainder of the Workshop • Stakeholders will present their views on the Business Trajectory and on trajectory synchronisation in different contexts • Presentation of a set of preliminary AIDL requirements • Gather your inputs on the way forward through open debate. • Enjoy and engage!

17. The Remainder of the Workshop • BACKUP SLIDES

18. Trajectory vs. Aircraft Intent What aircraft trajectory IS: • The evolution of certain aspects of the aircraft motion (geometry, kinematics and kinetics) • A time sequence of aircraft motion states (e.g. a sequence of 4D points) • The output of the trajectory computation process What aircraft trajectory is NOT: • A set of constrains that the aircraft motion must comply with (e.g. follow a specified CAS/Mach speed schedule) • The specification of strategies to be implemented by the aircraft or objectives to be fulfilled by its motion (e.g. an RTA to be met) What aircraft intent IS: • An unambiguous description of how the aircraft is to be operated within a timeframe • An abstraction of the flight instructions issued by the Pilot/FMS to manage the aircraft behavior • The input to the trajectory computation process What aircraft intent is NOT: • A flight plan • A sequence of 4D waypoints with a set of constraints to comply with • ATC instructions • A predicted trajectory

19. Formalization of the Concept of Aircraft Intent • Instructions: • They capture basic commands and guidance modes at the disposal of the pilot/FMS to direct the operation of the aircraft • They can be seen as minimal indivisible pieces of information describing distinct manners of closing one of the aircraft motion’s degrees of freedom • An instruction is characterized by a mathematical equation that is to be satisfied simultaneously with the equations of motion during a certain time interval, denoted as the execution interval • Operations: • They represent an elemental aircraft behaviour that determines its motion unambiguously during a specific time interval denoted as the operation interval • An operation is the result of a set of compatible instructions simultaneously active during the corresponding operation interval

20. Lexical Rules Vertical Instructions Syntactical Rules Speed Instructions Propulsive Instructions Configuration Instructions Lateral Instructions AIDL Overview: Elements AIDL Alphabet Grammar • Lateral: Aircraft bearing • Law: Constant • Value: 175º • Speed: CAS • Law: Constant • Value: 280 Knots • Configuration: Flaps • Law: Constant • Value: 15º